Adjusting for 30-hour undigested neutral detergent fiber in substitution of wheat straw and beet pulp for alfalfa hay and corn silage in the diet of high-producing cows

Effects of complete substitution of dietary grain and protein sources with by-products on the production performance of mid-lactation dairy cows fed diets based on barley silage under heat-stress conditions

This study evaluated the effects of replacing cereal grains and soybean meal with by-products (BY) on production performance, nutrient digestibility, ruminal fermentation, nutrient recovery, and eating and chewing behavior of moderate-producing dairy cows under heat-stress conditions. Twelve multiparous Holstein cows (116.7 ± 12.01 d in milk; 42.7 ± 5.06 kg/d milk yield; 665 ± 77 kg body weight; mean ± SD) were used in a replicated 3 × 3 Latin square with 28-d periods (21 d for diet adaptation and 7 d for sampling and data collection). Cows were fed a total mixed ration containing a 39.2:60.8 ratio of forage to concentrate throughout the experiment. All diets were formulated to be isoenergetic and isonitrogenous, with different concentrates. Diets were (1) control diet based on cereal grains (CON: ground corn and ground barley, plus soybean meal); (2) sugar-rich BY diet (S-BY-CM: beet pulp, citrus pulp, and liquid molasses, plus canola meal); and (3) cereal grain BY diet (CG-BY: rice bran, corn germ meal, wheat bran, barley sprout, and broken corn). Our results showed that replacing grains with BY increased neutral detergent fiber intake and digestibility but decreased starch intake, human-edible energy, and human-edible protein. Milk yield and dry matter intake (DMI) decreased more in cows fed the CG-BY diet compared with the other 2 treatments. In contrast, no significant differences were observed between the CON and S-BY-CM diets in terms of milk yield and DMI. The S-BY-CM diet increased energy-corrected milk production compared with the CG-BY diet (36.2 vs. 34.3 kg/d), but CG-BY enhanced feed conversion efficiency compared with the other 2 treatments. Although the S-BY-CM diet prolonged the eating and sorting of small particles, neither of the dietary treatments affected chewing activity or ruminal pH 4 h after feeding. Furthermore, both diets containing BY contributed to an increase in milk fat content in comparison to the CON group. Additionally, the CG-BY and S-BY-CM diets demonstrated better performance than the CON diet in terms of human-edible feed conversion efficiency for protein and energy. The results indicated that S-BY-CM can completely replace barley and corn grain in the diet of mid-lactating dairy cows exposed to heat-stress conditions without any negative effect on production and ruminal pH. However, the inclusion of CG-BY did impair DMI, milk yield, and digestibility of nutrients and is not recommended during heat-stress conditions.

Adjusting for 30-hour undigested neutral detergent fiber in substitution of wheat straw and beet pulp for alfalfa hay and corn silage in the dairy cow diet: Chewing activities, diurnal feed intake, and ruminal fermentation

This experiment investigated the effects of replacing alfalfa hay (AH) and corn silage (CS) with wheat straw (WS) and beet pulp (BP) in diets with similar forage 30-h undigested neutral detergent fiber (uNDF₃₀) on chewing behavior and ruminal fermentation of lactating cows. Twelve multiparous Holstein cows (51 ± 3 kg/d of milk; days in milk = 97 ± 13; mean ± standard error) were housed in individual stalls and used in a replicated 3 × 3 Latin square design with 28-d periods. Experimental diets were (1) 0% forage uNDF₃₀ from WS (WS0, contained 2% BP); (2) 50% forage uNDF₃₀ from WS (WS50, contained 7.6% BP); and (3) 100% forage uNDF₃₀ from WS (WS100, contained 12.4% BP). From 0 to 2 h after the morning feeding, there was a tendency observed for a quadratic effect on dry matter intake (DMI), with cows fed WS50 consuming the greatest amount of DM (9.19 kg). Later DMI (4 to 6 h and 6 to 24 h postfeeding) decreased as dietary proportion of WS and BP increased. Increasing WS and BP decreased eating behavior, but had no detected effect on rumination time (455 min/d), which resulted in a linear reduction in chewing time (the sum of eating and rumination activities). As WS and BP inclusion increased, the number of meals decreased linearly, whereas time between meals, eating rate, and meal size per kilogram of DM increased linearly. Increased dietary inclusion of WS and BP tended to decrease total ruminal VFA and resulted in a linear decrease in propionate but an increase in acetate proportion and ammonia-N concentration in the rumen. Overall, the substitution had no effect on rumination activity, possibly suggesting that a combination of WS and BP could be used in dairy cow rations as substitutes for high-quality forages when WS was added to maintain the uNDF₃₀ level.

Effects of maize silage substitution with sugarbeet or citrus pulp ensiled with corncobs on growth performance, digestibility, and economic benefits in buffalo calves

Ensiling of high-moisture agro-industrial wastes with dry roughage as animal feeds may be a secure way to reduce the feeding cost. The objective of this study was to investigate the effects of either sugarbeet or citrus pulp ensiled with ground corncobs and used as a replacement of maize silage or maize fodder in total mixed ration (TMR) for fattening of buffalo calves. Twenty male calves of Nili-Ravi buffalo (aged 14 ± 2 months weighing 133 ± 5 kg) were randomly assigned to one of four iso-nutritious (12% CP and 69% TDN) experimental diets with 50:50 forage to concentrate ratio (dry matter basis) as: (1) TMR maize silage, (2) TMR sugarbeet pulp ensiled with corncobs, (3) TMR citrus pulp ensiled with corncobs, and (4) TMR green maize fodder with wheat straw. All calves received TMRs for ad libitum intake twice daily for 80-day period. Daily feed intake, fortnightly body weights, and digestibility and N balance study during last 15 days were recorded of individual animals. The calves fed TMR sugarbeet pulp silage got highest daily gain (856 g/d, P < 0.05) than citrus pulp silage (776 g/d) or green maize fodder (704 g/d). Average intake of nutrients was same among all the calves. Feed conversion ratio and digestibility of DM, NDF, and ADF were higher (P < 0.05) with TMR sugarbeet pulp silage compared to other TMRs. Economic benefit (output/input) with TMR sugarbeet pulp silage had 15.46, 34.27, and 37.36% higher effect for fattening of buffalo calves compared to citrus pulp silage, green maize fodder, and maize silage-based TMRs, respectively. In conclusion, sugarbeet pulp ensiled with ground corncobs is simple and appropriate method for silage making and its inclusion up to 50% of DM in TMR had pronounced economic impact to the production of buffalo calves.

Improvement of feed intake, digestibility, plasma metabolites, and lactation performance of dairy cows fed mixed silage of sugar beet pulp and rice straw inoculated with lactic acid bacteria

A study was conducted to investigate the inclusion effects of sugar beet pulp and rice straw mixture silage with inoculation (BRMS), in place of whole-plant corn silage (CS), on the dry matter intake, total-tract nutrient digestibility, plasma metabolites, rumen fermentation, and lactation performance in high-production dairy cows. Sixteen multiparous Holstein cows (body weight, 622 ± 35 kg; days in milk, 90 ± 11 d; mean ± standard deviation) were used in our experiments; the experiments were based on a repeated 4 × 4 Latin square design for 21 d, and each experimental period consisted of 14 d of adaptation, followed by 7 d of data collection. The 4 dietary treatments used were (dry matter basis): (1) 0% BRMS and 28.6% CS (0BRMS); (2) 4.3% BRMS and 24.3% CS (15BRMS); (3) 8.60% BRMS and 20.0% CS (30BRMS); and (4) 12.9% BRMS and 15.7% CS (45BRMS). The increasing inclusion of dietary BRMS was observed to linearly increase the total volatile fatty acids and the propionate concentration. The dry matter intake and digestibility values of neutral detergent fiber and acid detergent fiber increased linearly as the percentage of BRMS increased up to 45%. Milk yield linearly increased with the increase in the content of BRMS (39.0, 39.8, 40.9, and 40.3 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). The increasing inclusion of dietary BRMS induced a decrease in the ammonia nitrogen and milk urea nitrogen concentration, leading to a linear increase in milk protein production (1.15, 1.26, 1.35, and 1.27 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). In conclusion, the diets with the replacement of CS with BRMS up to 45% were beneficial to the production performance of high-production dairy cows, indicating that this method may be an appropriate use of sugar beet pulp and rice straw.

Feeding low-quality date leaves as a substitute to conventional forages in dairy cows diet: effects on digestibility, feeding behavior, milk yield, and feed efficiency

This study investigated the possibility of integrating date leaves (DL) as a partial or complete substitute for conventional forage fibre sources into the diet of dairy cows. Nine Holstein cows were assigned to a replicated 3×3 Latin square design, and offered 1 of the 3 diets containing no DL (DL-0), or finely chopped DL partially (50%, DL-50) or completely (100%, DL-100) substituted for lucerne hay and maize silage. The replacement of the forages by DL was established such that the forage NDF (24.5%) was similar across diet despite the decreased forage: concentrate ratio from 0.45:0.55 to 0.33:0.67. Diets were similar in concentration of crude protein and starch, while the indigestible forage NDF (iNDF) increased from 7.2 to 15.4% of DM. Results showed that increasing DL inclusion linearly decreased nutrient intake and digestibility. Moreover, a trend toward a linear decrease in milk yield and percentage of milk protein and lactose were observed with increasing DL proportion in the diet. However, ruminal volatile fatty acids concentration, milk fat content, and feed efficiency were similar across the treatments. A quadratic trend was observed for eating and ruminating time by feeding DL, with the highest values found for cows fed DL-50. Replacing forages with finely chopped DL was effective to meet the fibre requirement, but reduced feed intake and milk yield possibly because of increased forage iNDF. However, conventional forages can be partially replaced with DL in the diet, particularly under forage shortage, because of maintained gross milk yield efficiency and reduced feed cost.

The effects of pelleted dried distillers grains and solubles fed with different forage concentrations on rumen fermentation, feeding behavior, and milk production of lactating dairy cows

The physical form of feeds can influence dairy cow chewing behavior, rumen characteristics, and ruminal passage rate. Changing particle size of feeds is usually done through grinding or chopping forages, but pelleting feed ingredients also changes particle size. Our objective was to determine if pelleted dried distillers grains and solubles (DDGS) affected the feeding value for lactating dairy cattle. Seven lactating Jersey cows that were each fitted with a ruminal cannula averaging (± standard deviation) 56 ± 10.3 d in milk and 462 ± 75.3 kg were used in a crossover design. The treatments contained 15% DDGS in either meal or pelleted form with 45% or 55% forage on a dry matter basis. The forages were alfalfa hay, corn silage, and wheat straw. The factorial treatment arrangement was meal DDGS and low forage (mDDGS-LF), pelleted DDGS and low forage (pDDGS-LF), meal DDGS and high forage (mDDGS-HF), and pelleted DDGS and high forage (pDDGS-HF). Dry matter intake and energy-corrected milk were both unaffected by treatment averaging 19.8 ± 2.10 kg/d and 33.9 ± 1.02 kg/d, respectively. Fat yield was unaffected averaging 1.7 ± 0.13 kg/d, but protein yield was affected by the interaction of forage and DDGS. Protein yield was similar for both low forage treatments but was increased by when pDDGS was fed in the high forage treatment (1.05 vs. 0.99 ± 0.035 kg/d). When forage concentration was increased, starch digestibility increased by 1.9 percentage units, crude protein digestibility tended to increase 1.1 percentage units, and residual organic matter digestibility decreased 3.4 percentage units. Pelleting DDGS increased digestibility of neutral detergent fiber (NDF) digestibility (49.2 vs. 47.5 ± 1.85%) and gross energy (68.2 vs. 67.1 ± 1.18%). Increasing forage increased ruminal pH (5.85 to 5.94 ± 0.052). Passage rate slowed from 2.84 to 2.65 ± 0.205 %/h when feeding HF compared with LF. Rumination time increased from 417 to 454 ± 49.4 min with increasing forage concentration but was unaffected by the form of DDGS or the interaction of forage and DDGS. Eating time increased with pDDGS (235 vs. 209 ± 19.8 min), which may be a result of increased feed sorting behavior. Pelleting DDGS increased preference for particles retained on the 8-mm sieve and decreased preference for particles on the 1.18-mm sieve and in the pan (<1.18 mm). Results confirm that increasing forage concentration increases ruminal pH, rumination time, and slows passage rate, but contrary to our hypothesis increasing forage concentration did not increase NDF digestibility. Results also suggest that pelleted DDGS do not appear to affect milk production, ruminal characteristics, or passage rate, but pelleted DDGS may increase sorting behavior of lactating Jersey cows and increase NDF and gross energy digestibility.

Effects of substitution of beet pulp for barley or corn in the diet of high-producing dairy cows on feeding behavior, performance, and ruminal fermentation

This study investigated the effects of substituting beet pulp (BP) for different grains (barley or corn) in the diet of high-producing dairy cows on intake, feeding behavior, nutrient digestibility, ruminal fermentation, milk production, and feed conversion efficiency. Eight second-parity Holstein cows (62 ± 2 d in milk; milk yield = 54 ± 1.2 kg/d; body weight = 624 ± 26; all mean ± SE) were used in a replicated 4 × 4 Latin square design during 4 periods of 21 d. Cows were randomly assigned to 1 of 4 treatments that were a 2 × 2 factorial arrangement of 2 grain sources (corn or barley) and 2 levels of BP inclusion [5 or 15% of dry matter (DM)] in the diet: (1) barley-based diet with BP at 5% of dietary DM; (2) barley-based diet with BP at 15% of dietary DM; (3) corn-based diet with BP at 5% of dietary DM; and (4) corn-based diet with BP at 15% of dietary DM. The increasing amount of BP in the diet was at the expense of decreasing an equal proportion of grain (barley or corn). All diets were high in concentrates (65% of diet DM) and formulated to have similar concentrations of energy and protein. The portion of feedstuffs that is potentially able to be consumed by humans is known as human edible. Accordingly, human-edible protein (HEP) and human-edible energy (HEE) inputs were calculated according to the recommended potential human-edible fraction of each dietary ingredient, and HEP and HEE outputs were determined as the amount of gross energy and true protein in the milk. Feed conversion efficiency (FCE) for HEP and HEE were expressed as output per input of each variable, whereas FCE for the production of fat-corrected milk (FCM) and energy-corrected milk (ECM) were expressed as the amount of each variable per DM intake. Results showed that substituting BP for grain did not affect DM intake, crude protein intake, or nutrient digestibility, whereas starch intake (5.70 vs. 7.43 kg/d for the low-BP vs. high-BP diets, respectively), HEP (2.34 and 1.92 kg/d), and HEE (186 and 147 MJ of gross energy/d) decreased. Treatments did not affect sorting and chewing activities, but increasing BP in the diet increased ruminal pH at 4 h after feeding (6.20 vs. 6.39) and milk fat content (2.92 vs. 3.15%). Similarly, FCE for ECM production (1.44 vs. 1.54) as well as FCE for HEE (0.653 vs. 0.851) and HEP (0.629 vs. 0.702) were greater in high-BP diets compared with low-BP diets. The interaction of BP and grain sources significantly affected FCE for ECM production, where improvements were more evident when BP was substituted for barley than for corn. The improvement in FCE for HEE was greater when BP was substituted for barley (0.236) rather than corn (0.161). In conclusion, the substitution of BP for barley or corn grains in high-concentrate diets of high-producing cows decreased starch intake, increased ruminal pH at 4 h after feeding, and improved FCE for FCM production. Substitution for barley, rather than for corn, promoted greater FCE for ECM production and HEE.

Substitution of wheat straw with sugarcane bagasse in low-forage diets fed to mid-lactation dairy cows: Milk production, digestibility, and chewing behavior

Sugarcane bagasse (SB) is a low-quality roughage source that is often plentiful during times of forage shortage. It is generally less costly compared with other conventional sources of forage. We hypothesized that SB could be used as a source of roughage for dairy cattle by replacing wheat straw (WS), another low-quality forage. This study evaluated the effects of replacing WS with SB in diets offered to mid-lactation dairy cows on milk production and fatty acid profile, intake, digestibility, chewing activity, and ruminal fermentation. Nine multiparous Holstein cows averaging (mean ± standard deviation) 105 ± 12 d in milk, 42.1 ± 2.9 kg of milk/d, and 617 ± 59 kg of body weight were used in a replicated 3 × 3 Latin square with 21-d periods. Treatments were (% of dietary dry matter, DM): (1) 0SB, diet containing 0% SB and 27% WS, (2) 9SB, diet containing 9% SB and 18% WS, and (3) 18SB, diet containing 18% SB and 9% WS. Sugarcane bagasse had greater organic matter (OM; 94.1 vs. 85.1% of DM), neutral detergent fiber (NDF; 86.2 vs. 76.4% of DM), acid detergent fiber (ADF; 62.9 vs. 45.2% of DM), and lignin (19.9 vs. 10.3% of DM) concentration, but less crude protein (CP; 2.63 vs. 3.72% of DM) concentration than WS. Sugarcane bagasse also had greater physically effective NDF (total dietary NDF multiplied by % of TMR on the 8-mm + 19-mm sieves, peNDF₈; 63.2 vs. 40.6% of DM) and undegraded NDF after 288 h of incubation (uNDF₂₈₈; 35.5 vs. 21.2% of DM) contents than WS. The undegraded NDF after 30 h of incubation (uNDF₃₀) content was similar for all diets; however, peNDF₈ concentration and proportion of long particles (retained on a 19-mm sieve) increased linearly as SB inclusion in the diets increased. Cows increasingly sorted against long particles as SB replaced WS. Intakes of DM (26.53 kg/d) and NDF (8.58 kg/d) did not differ among the treatments, but intakes of OM and CP decreased, whereas ADF and uNDF₂₈₈ intakes increased with SB inclusion level. Total-tract digestibilities of OM, CP, and NDF decreased linearly as SB replaced WS. Milk yield (37.0 kg/d), energy-corrected milk yield (ECM; 38.2 kg/d), feed efficiency (1.44 kg ECM yield/kg DM intake), and milk composition (fat, 3.89%; true protein, 2.90%) did not differ among diets. Increasing SB concentration of the diet linearly increased rumination time, but ruminal pH (ruminocentesis, 4 h after feeding) decreased. Total volatile fatty acid concentration increased linearly, whereas acetate:propionate decreased linearly, as SB replaced WS. The results indicate that replacement of WS with increasing levels of SB in low-forage diets with similar uNDF₃₀ concentrations did not affect performance of mid-lactation dairy cows. We conclude that SB can be used as a fiber source in diets fed to dairy cows in mid-lactation; however, the decrease in total-tract digestibility of diets may decrease lactational performance when fed to high-producing dairy cows.